Differences in Types (huge pic file)

[Mason]

All the time people are asking for the different types of lowers and uppers and how to check.

They can use the search function, but sometimes it's hard to yield any results when you're so new that you're not quite sure what you're looking for.

Here it is:



This is a Type I lower receiver. This is the original, as designed by FN. They designed this to be as light as possible. Notice the 90 degree lightening cut on the recoil plate. Also, on the inside of the lower receiver, where the fire control group is located, there are lightening cuts there.



This is a Type II lower receiver. This receiver came to be during the testing of the FALO rifle. After thousands and thousands of fully-automatic firing without a stop, the original Type I receiver developed a hair-line crack at the rear of the receiver. So they strengthened that area by making the cuts radiused and not cutting some parts on the upper receiver. Here is a Type II upper receiver:

I outlined the lightening cuts in red. Take note of the strengthened area at the rear of the receiver where the locking foot is. They did not cut this area to increase the strength of the receiver.



This is a Type III lower receiver. This was the last development of FAL receivers. Notice how there is no lightening cuts on the recoil plate. They did this to save time and cost of manufacturing. Imbel used this on their receivers. This is the heaviest and strongest receiver made, but it was not developed to be strong. It was developed to save time and cost. It just turns out that it is also the strongest.

NOTE: I have personally seen several Type I and Type II FALs with over 10,000 rounds fired through them and there is nothing wrong AT ALL with the original receiver. If you are new to FALs, don't think that you have to have a Type III because it is the strongest. During the testing of the FALO, they fired thousands and thousands of rounds in a matter of hours without stopping and a HAIRLINE crack developed. The gun did not fail and no explosion or kaboom took place.

Here is a side-by-side image of all three types of lower receivers.


Here is a correct Type I upper receiver on a Type I lower receiver.


Here is a correct Type III upper receiver on a Type III lower receiver.


This is what happens when you mix and match. This a Type I lower receiver on a Type III upper receiver.


A Type I or Type II lower receiver looks right at home on a Type III upper receiver. Only a knowledgable person would ever know the difference. If you use a Type III lower receiver on a Type I or Type II upper receiver, you can easily dremel the recoil plate to conform to the lightening cuts on the upper receiver. It must also be said that you can machine Type III upper receivers into both Type I and Type II upper receiver configurations, but this is an extremely tedious task and requires a milling machine. It is relatively expensive to have this done.

[hanko]

Mason, very NICE post. I've never seen a better explanation of receiver descriptions & differences.

Thanks for the time you spent



-hanko

[AndyC]

Yeah, what took you so long?

[Abominog]

Uh oh, looks like Junior has made it to the big time...

hey mods, let's move this to R&D!



ps Mason, next, we'd like to see the variations in the Type A stocks!

[KIT]

Very informative post, I agree that it belongs in the R & D Forum.
Well Done Mason


Cheers


-KIT-

[Radio]

I sorta feel like Mr. Magoo looking at most of those photos.

[adam762]

Nice work. I think a lot of that is discussed in THIS thread, though. I agree, it can be hard to search the R&D section sometimes.